Apparatus for punching out workpieces



March 19, 1968 E. M. SPENGLER 3,373,643

APPARATUS FOR PUNCHING OUT WORKPIECE'S Filed Feb. 11, 1966 InventorErnst M Spengler By his Attorney Unite States 3 373,643 APPARATUS FORPUI JCHING OUT WORKPIECES Ernst Maximilian Spengler, Olfenhach, Germany,asslgnor to United Shoe Machinery Corporation, Flemington,

N.J., and Boston, Mass, a corporation of New Jersey Filed Feb. 11, 1966,Ser. No. 526,863 9 Claims. (Cl. 83-620) ABSTRACT OF THE DISCLGSURE Thisinvention relates to press type machines and is directed moreparticularly to an apparatus for punching or stamping out workpiecesfrom sheet material.

Such machines are known in the art and comprises a series of cuttingtools or knives rigidly attached to a support. The knives are made ofstrip steel shaped in the form of the workpiece to be cut. Usually, asupport plate carries a plurality of strip steel knives arranged asclose to each other as possible and engageable with a sheet of leather,rubber, plastic, metal, web of textile material, or the like, for thepurpose of cutting out workpieces required in the construction ofclothes, shoes, etc. Difliculty has been experienced inthe use of suchmachines because of the jamming of waste portions of the sheet materialbetween adjacent knives. The removal of such waste portions is timeconsuming and sometimes dangerous to personnel. Further, the cutworkpieces and the knives may be damaged during the waste removaloperation. Still further, the knives must be spaced apart a suificientdistance to permit a tool of some sort to be projected therebetween forthe purpose of removing the waste material.

Accordingly, it is an object of the present invention to provide meanswhich permit the quick and easy removal of waste material from betweenadjacent knives.

A further object of the invention is to facilitate arrangement of theknives on a support as closely together as possible in order to reducethe percentage of waste material.

Yet another object of the invention is to facilitate the removal of thecut workpieces from within the knives.

With the above objects in view, and in accordance with a feature of theinvention the illustrative apparatus comprises a plurality of cuttingknives arranged with very slight spacing from each other on a commonsupport plate, each knife being yieldingly connected to said supportplate. Such a yielding connection may, for example, be an elasticconnection comprising one or more pins, screws or rivets and at leastone elastic washer of rubber or like material arranged between the baseof a knife and the support plate, the rubber washer having sufiicientthickness to provide for a clearance between the back of the knife andthe surface of the support plate facing the back of the knife. In thepreferred embodiment of the invention two elastic washers are provided,one of the washers being arranged between the back of the knife and thesupport plate while the other washer reaches through an aperture in theback of the knife. A pin or the like extends through both washers,connecting the knife to the support plate in a manner which permits somefreedom of movement of the knife.

Reference is made to the accompanying drawings in which there is shownan illustrative embodiment of the invention from which its novelfeatures and advantages will be apparent. It is to be understood,however, that the present invention is by no means limited to theparticular constructions shown in the drawings, but also comprises anymodifications within the scope of the appended claims.

FIG. 1 is a sectional view of one form of apparatus embodying theinvention;

FIG. 2 is a sectional view through another embodiment of the invention;

FIG. 3 is a sectional view through still another embodiment of theinvention, and

FIG. 4 is a plan view of the apparatus of FIG. 1.

Referring to FIG. 1, it may be seen that the illustrated machineincludes a support plate 2 to which are yieldingly connected a pluralityof strip steel knives 4. The spacings between adjacent knives is minimalin order to reduce the amount of waste material generated by eachcutting operation. Each knife 4 has a cutting edge 6 and is of a shapecomplemental to the desired shape of the Workpiece to be punched out.Each knife is, depending upon its configuration and size, attached toone of several crosspieces 8. The connection between each knife 4 andits crosspieces or pieces 8 may be accomplished by Welding or soldering,or in any other suitable manner.

The connection between the crosspiece 8 and the support plate 2comprises a pin 10, screw, or rivet or the like, extending through atleast one yieldable elastic Washer 12. It is to be understood, however,that the pin 10 need not necessarily extend through the washer 12inasmuch as elastic blocks 14 (FIGS. 1 and 4) may be ce mented betweenthe crosspiece 8 and the support plate 2 away from the screw. As isnecessary for controlling the degree of yielding of the knives relativeto the support plate, the elastic means, such as washers 12 or blocks14, may be used in combination, as shown in FIG. 1.

The thickness and elasticity of the elastic means is selected to providea clearance between the back of each knife, i.e., the crosspiece, andthe surface of the support plate which provides a space into which theknife can yield in the punching operation. In the invention asillustrated in FIG. 1, the knives are attached to the support plate bymeans of screws 10 and two elastic washers 16 and 12. One washer 12 isplaced between the surface of the support plate 2 and the crosspiece 8.The other washer 16 extends through an aperture in the crosspiece 8. Thescrew or rivet 10 extends through both washers 16, 12.

FIG. 2 shows that the elastic washers or blocks may be replaced byspring means 18 such as a leaf or plate spring. The embodiment of FIG. 2also illustrates the use of an ejector means 20 (seen in the right handknife of FIG. 2), such as a foam rubber pad within the space bound bythe knife. The pad 20 is compressed as the space bound by the knife isfilled with the punched out workpieces and the elasticity of the padejects or greatly facilitates the ejection of the punched outworkpieces.

FIG. 3 shows still another embodiment of the invention utilizing elasticor resilient washers 22 cemented or otherwise attached to the supportplate 2. In this embodiment the screw 10 serves merely to connect thecrosspiece 8 to the washer 22.

Because of the yielding action of the elastic or spring means employedaccording to the invention, the individual knives can move slightlyrelative to each other, permitting quick and easy removal of wastematerial disposed between adjacent knives. The knives are movable in adirection normal to the plane of the support and may be tilted about thepins 10. In addition, the embodiments illustrated in FIGS. 1 and 3 havea slight degree of freedom in a direction parallel to the plane of thesupport.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. Apparatus for punching out workpieces from sheet material comprisinga support, punching means, each of said punching means having a backportion, and yieldable means for attaching the punching means to thesupport, said yieldable means comprising at least one yielding memberconnected :at one end to said support and connected at its opposite endto the back portion of a punching means, said yielding member permittingthe punching means to move in directions normal to the plane of saidsupport and in directions other than normal to the plane of saidsupport.

2. Apparatus for punching out workpieces from sheet material comprisinga support, a plunality of punching knives disposed on said support, eachof said knives having a back portion, and yieldable meansinterconnecting said support and each knife, said yieldable meanscomprising at least one yielding member connected at one end to saidsupport and connected at its opposite end to the back portion of aknife, said yielding member permitting the knife to move in a directionparallel to the plane of said support.

3. Apparatus for punching out workpieces from sheet material comprisinga support, a plurality of punching knives disposed on said support, eachof said knives having a back portion, and yieldable meansinterconnecting said support and said knives, said yieldableinterconnecting means comprising at least one yielding member disposedbetween the back portion of a knife and the support, said yieldingmember permitting movement of said knife relative to said support indirections having a vector parallel to the plane of said support.

4. The invention according to claim 3 in which said yielding member isan elastic washer.

5. The invention according to claim 3 in which said yielding member isan elastic block.

6. The invention according to claim 3 in which said yielding member is aspring member.

7. Apparatus for punching out workpieces from sheet material comprisinga support, :a plurality of punching knives disposed on said support,each of said knives having a back portion having an aperturethercthrough, and means interconnecting said support and each of saidknives comprising a headed pin disposed in said aperture and connectedto said support, and a yielding member having an aperture and disposedbetween said support and the back portion of a knife, said pin disposedin the aperture of said yielding member, said yielding member permittingmovement of said knife about said pin.

'8. Apparatus for punching out workpieces from sheet material comprisinga support, a plurality of punching knives disposed on said support, eachof said knives having a back portion with an aperture extendingtherethrough, and means interconnecting said support and each of saidknives comprising a headed pin disposed in said aperture and connectedto said support, an elastic washer disposed between a knife and saidsupport, and a second elastic washer disposed partly within saidaperture, said pin extending through said elastic washers.

9. In an apparatus for punching outworkpieces from sheet materialcomprising a support and a plurality of punching knives disposed on thesupport, that improvement comprising means for mounting said knives onsaid support to permit movement of each of said knives relative to saidsupport in a direction parallel to the plane of said support, saidmounting means comprising at least one yieldable member disposed betweena knife and the support, and means for connecting the knife to thesupport with the yieldable member retained therebetween.

References Cited UNITED STATES PATENTS 2,265,649 12/1941 Krehbiel 83-663X 2,821,871 2/1958 Sarno 83-128 X 3,025,727 3/1962 Smith 83-128 X3,289,516 12/1966 Bohrer et a1 83698 X FOREIGN PATENTS 406,817 8/ 1966Switzerland.

WILLIAM S. LAWSON, Primary Examiner.

